First, I'd quickly rap a towel around myself and punch, punzone him in the face. Then I'd yell "WTF is wrong with you?!" After that, I push him outta the bathroom, close the door and lock it. (if there happened 2 B a lock)
I'd put on a towel, tell him I'd be back in a minute, come back with a crowbar and beat the shit out of him because he sounds like a girl and he's a fag